Over the Side Vat Heater.

Buy Over the Side Vat Heater Heaters


Call Jamie on 07897 246779 to discuss your Over the Side Vat Heater needs.

We offer bespoke Vat Heaters for chemical solutions, oil, and water, in both Single Phase Single Element and Three Phase Three Element options.

The image below shows all of the various shapes and bends which can be achieved if you are unable to accomodate the drops listed in the table further down the page.

over the side vat heater available bends
over the side vat heater available bends

Our heaters feature:

  • Heavy Duty Moulded ABS Terminal Box. 3ph – 300x100x100mm, single phase 100x100x100mm.
  • IP54 rated Terminal box – suitable for outdoor use,
  • 12.7mm or 1/2″ elements.
  • Moulded cable entry glands.
  • Removeable cover for easy access to wiring.
  • Adjustable moulded mounting blocks.
  • Colour coded for easy identification of element sheathing material.
  • Cold section markings for visual prevention of liquid level drop.
  • Robust construction.

Over the Side Vat Heater Sheath materials available include:

Pros & Cons

As with everything in life, it is all about the compromise. Over the side vat heaters have advantages over through the side heaters, but also there are downsided to be considered too.


The main benefit to putting your heat in through over the side heaters is that the tank does not have to be drained in order to switch out a dead heater for a new one. As most “through the side” immersion heaters are located at the bottom of the vessel, as heat rises, so the vessel will have to be all but completely drained to change a screw in heater. Also, this “whip ’em out” flexibility allows these vat heaters to be used in multiple vessels. As long as they are switched off & allowed to cool before relocating, mind you! That school boy error will prove expensive, indeed.


The downside to applying heat at the top of the vessel will become clear if your liquid  level drops. If hot element is exposed to air, it rapidly becomes a fire hazard. And It will go BANG sooner rather than later. Thus, the default arrangement of 6″ on the horizontal (Y in the schematic above) gives you 12″ to play with, Matron! Therefore, we can lose the horizontal to give you 18″ of room for level drop. But the downside to this is that the terminal box must be suspended over the solution, both exposed to rising vapours and in danger of dropping into solution. Which will not end well, hence the recommendation at the top of the page.

Additionally, the cost of a Vat Heater Thermostat is another unfortunate downside, at the same cost as a single phase heater! An immersion heater, fitted thru the side of the vessel, comes with a stat pocket. Thus a bargain £30 stat can be added. Albeit a somewhat “Agricultural” one, with a variance of circa +/-7°c. This suits most customers, but if half a degree accuracy is required, a PID Controller will have to be fitted. This could be achieved in a vat stat, but as it is an entirely different & seperate housing, the cost is horrible at £200+, irrespective of SS, Titanium or PTFE.

Browse Over the Side Vat Heaters.